Few people anticipated Port Adelaide beating Geelong at the start of the day. Photograph: Morne de Klerk/Getty Images

Port Adelaide beat Geelong by 40 points to inflict the Cats' first loss of the season and stamp themselves as genuine flag contenders. The Power prevailed 16.11 (107) to 9.13 (67) to join Hawthorn and the Cats at the top of the table.

The trio all have five wins and a loss after Port dismantled the Cats in grand style before a raucous home crowd of 47,007 spectators.

The Cats were well-served by Matthew Stokes (28 disposals), Steve Johnson (25 touches) and Mitch Duncan (27 possessions) but butchered a host of scoring chances with errant goal-kicking. Key forward Tom Hawkins slotted three goals from limited opportunities and Josh Walker booted two but the Cats paid the price for wasteful goal shooting, particularly in the second quarter.

In a freewheeling fixture, Geelong held a two-point advantage after both sides kicked four goals in the opening quarter. Both teams then had five scoring shots in the second term: the Power logged 4.1 while Geelong returned just five points.

Geelong's inefficiency helped Port create a three-goal break at halftime - a margin the rampant hosts doubled in the initial six minutes of the third term when the influential Gray slotted his second.

The Cats briefly rallied but could only get within four goals before Port kicked away again, taking a defining 38-point buffer into the last quarter.

Port's reigning club champion Wingard then capped a stunning Port victory with two quick goals in the last quarter.

Patrick Dangerfield fends off the attention of the Western Bulldogs. Photograph: David Crosling/AAP Image

Adelaide overcame a slow start and late scare to register a nine-point victory over Western Bulldogs at Etihad Stadium on Sunday, their third AFL win on the trot.

The Crows conceded the opening four goals of the contest, but dominated the second and third quarters as they poured on eight consecutive goals to run out 13.14 (92) to 12.11 (83) winners.

From the moment Tory Dickson kicked truly to give the hosts a game-high 28-point lead early in the second quarter, it was all Adelaide as they clicked into gear and James Podsiadly ran rampant.

The Bulldogs' next goal came in the third minute of the final term, when key forward Stewart Crameri turned crumber in a goal-square scramble.

But the Bulldogs some how seized the momentum after Crameri's major and 13 minutes later they had regained the lead when Dickson dobbed his third goal.

With the help of stand-in skipper Rory Sloane the visitors steadied, Matthew Wright and Josh Jenkins both waltzing into the goal square unopposed to kick the easiest of clutch goals.

Bulldogs Lachie Hunter and Luke Dahlhaus both missed goals in response, and they eventually ran out of time after a kicking-in error from Jack McCrae gifted a goal to Eddie Betts.

Jenkins and Podsiadly both booted three goals, making the most of an undersized and undermanned Bulldogs defence that was minus Dale Morris (ankle) and Jordan Roughead (shoulder).

Both the second and third quarter ended with a heated scrimmage.

Dangerfield was felled by Daniel Giansiracusa shortly before three-quarter time and looked to be in much discomfort for the remainder of the game, while Adam Cooney and Rory Laird needed to be separated by teammates at half time.

Dangerfield was again among the Crows' best, tallying 29 disposals, seven tackles and seven clearances.

Tom Lynch kicked two goals and clutched seven marks, with Crows coach Brenton Sanderson set to make a tough call as he mulls who to take out of the team for fit-again spearhead Taylor Walker.

There were plenty of highlights for the Bulldogs, and not just from usual suspects Matthew Boyd, Ryan Griffen, Adam Cooney and Bob Murphy.

Unfortunately for locals, the vast majority of them came amidst a four-goal blitz in the opening 15 minutes of the match.

Tom Campbell twice outmarked Kyle Hartigan with ease in the opening three minutes, while Dickson looked similarly dangerous in spurts.

Cyril Rioli of the Hawks is congratulated by Bradley Hill during an impressive performance in his team's victory over Richmond. Photograph: Quinn Rooney/Getty Images

Hawthorn’s Cyril Rioli swatted aside criticism about his form with a best-afield performance in their 66-point win over Richmond. Rioli tore the game apart with four goals in the third term and led the Hawks to the 18.10 (118) to 7.10 (52) win at the MCG.

Hawks defender Josh Gibson was reported when he went to spoil Reece Conca on the wing late in the last quarter and cannoned into him. The heavy contact sparked a melee and forced Conca from the field.

After quiet games against Gold Coast and Geelong, Rioli was back to his best at Richmond's expense. A Sunday newspaper column by former Essendon great Matthew Lloyd questioned whether the utility was over-rated. The two-time premiership player and 2012 All-Australian gave an emphatic response. Rioli was prominent from the start as the Hawks jumped Richmond and took 19-point lead at quarter-time.

After losing for the first time this season last week, Hawthorn started much better and pressured the Tigers into costly turnovers. Richmond matched Hawthorn in the second term, but did not capitalise on their good work and the Hawks kicked two goals to one.

The Tigers had won their last two games against Hawthorn and there were hopes of a second-half comeback. The first two minutes of the third term put paid to that. Rioli and then David Hale kicked quick goals to kill off the contest. Rioli's second goal of the quarter came when he superbly intercepted a handball from Ricky Petterd.

It was a big match for the Hawks, with Sam Mitchell and Shaun Burgyone playing their 250th games. Mitchell, Burgoyne and captain Luke Hodge all featured in Hawthorn's best. The loss leaves the Tigers in growing trouble with only two wins from their opening six games.